@asadking
I bought a brand new red 5800XM just last month, and it had the ear piece problem. I guess i must have gotten an old batch or something, even though the warranty was fresh.
Either way, first of all, the problem wasn't that major. It would come and go on it's own, and would only bother me 5-10% of the time.
Secondly, it's VERY EASY to fix. The front panel of the 5800 doesn't require you to open any screws or anything, and can be snapped off using the plectrum provided with the phone. After that, you just remove the ear piece, straighten two pins, and put the cover back on. I did this just last week, and phone is working perfectly now. There are several videos on youtube demonstrating the fix.
it's an awesome phone, as long as you are looking for a smartphone. if you wont be using the features, then don't go for a phone as bulky as this. get something thinner and lighter.
P.S when you do get the phone, install google maps. the built in GPS receiver is awesome (tells you your position, approximated to 5 meters, on google earth). Also, the phone camera is excellent if you use the dual led flash. The resistive touch screen is better than the one you find in most HTC phones. A lot of reviews complain that it is slow, but trust me, it's very very fast, especially once you upgrade the firmware.